People who are ill, elderly, menstruating or pregnant are exempt, but otherwise, every other able-bodied Muslim is expected to sacrifice as a sign of faith.

People stay up late to break their fast and get up in the early morning hours so they can eat before daybreak.

This results in shorter sleeping hours which can cause people to become more lethargic later on in the day.

"The productivity of workers declines in the holy month by 35-50% as a result of shorter working hours and the change in behaviour during this month," says Samer Sunnuqrot, an economist based in the Jordanian capital Amman.

He points out that people become less efficient and that they might even become bad tempered.

The positive side of Ramadan for business people is a higher demand for goods and services and higher consumptionSamer Sunnuqrot, Economist, Amman, Jordan

"Decisions and meetings will be postponed until the period of Ramadan is over, especially in governmental institutions."

He adds: "This causes lower productivity and performance and might incur losses for business people because of the postponing of decisions and processing of government transactions."

Increase in demand

Levels of observance of Ramadan will vary in different countries and cultures but most Muslims will conform to some extent with the requirements of the fast.

In Saudi Arabia, employees holding senior posts are not entitled to work reduced hours and are required to work the hours that are necessary to carry out their duties in full.

In Algeria meanwhile, control and fraud repression brigades have closed more than 1,500 business premises because of non-compliance with the rules regarding fasting during the day, according to the trade ministry.

In most countries, some restaurants will remain open throughout the day, with a sign saying that food is served to non-Muslim people only.

Image caption
After breaking their fast people will meet in cafes to talk and smoke a shisha pipe

Fasting during the day does not lead to a fall in demand for food.

According to Mr Sunnuqrot, people tend to consume more and even purchase more than they actually need.

"The positive side of Ramadan for business people is a higher demand for goods and services and higher consumption," he says.

"That often means higher prices, which translates into higher profit margins for merchants, retail stores, restaurants and cafes - especially those which arrange amusement programmes for after iftar [the breaking of the fast at the end of the day]."

In Bangladesh, the government has temporarily halted the export of fish to ensure there is enough for domestic consumption and to prevent the prices rising.

The higher consumption equates to higher economic growth, although this is generally only a short-term effect.